The load data button only becomes active after doing a measurement. It is pretty annoying that I: 1) have to physically connect the tracer, 2) run the "get parameters" routine, 3) do a measurement, 4) delete the measurement, and only then can I 5) load a previous dataset........

The data file management is also not very transparent. It seems that all basic commands like "New", "Open", "Close" and "Save" have been replaced by only two that function as "Merge" and "Save as"

Cheers,

Nic

P.S. Thanks for the software update. It seems to have solved my data export problems.

I do not intend to hijack this thread, it’s just that I would like to ask some information from those who have an original SMPS from HP. Also, the following information might be of use for anybody else building this tracer and purchasing a low-cost HP clone power supply.

I bought a low-cost new power supply from eBay Germany (~18 Euro), sold as a ‘replacement’ for the original HP. Of course, it had to be opened up, because:

That’s what I do with any electronic device since childhood…

I want to remove the primary IEC connector and install a loose chassis-mounted one with a power switch in the middle.

The outgoing secondary cable is in the way for putting this PSU inside an enclosure with the tracer PCB (like locky_z did himself in one of his pics).

Now, after opening up this low-cost PSU, it became clear it is low-cost indeed. There are a lot of missing components on the PCB; it makes me afraid that perhaps the protection circuit is omitted, and the output filtering seems commercially undressed in particular.

The capacitor brand isn’t the best either, and because I’m ordering parts from Digikey anyway this week, I’ll order some good quality caps with it.

The HV caps (Ltec, TY series) will be replaced by Nippon Chemi-Con KXG series

The LV output caps (black = Lelon LXK, blue is Ltec LZG) will be replaced by United Chem-Com KY series
Of course I could just order exact replacements, but I have some hesitation; it looks like the lowest possible cost solution has been installed here… so if ordering anyway…. let’s get the right caps.

The two output filter/buffer capacitors in the picture are in fact in parallel, but of different make and value

Please note that the PCB silk screen printing for the smaller blue cap shows a circle suggesting a larger size capacitor, and the larger black one has 7 mm additional headspace (so it could have been a higher CV cap).

In other words, it gives a (subjective) feeling of some cost cutting.

Question #1: do such caps always have to be of different value (for some reason as circuit resonance/oscillation)?

Question #2: what are the capacitor values in the original HP power supply packs?

Question#3: I could fit in 2x 680uF caps (2310 mA RC each), would there be any reason not to do so?

Then, some more bad feelings. A jumper is installed where a resistor (jumper across R59 under the black cap in the picture below) is printed on the PCB: this jumper is between the output capacitors and the choke (the final outgoing cables are connected to the other side of the choke). Checking out the web learns that there is indeed very often a resistor to further reduce any remaining ripple.

Question #4: is there a resistor installed in the original HP power supply packs, and what is it value? What would be the power rating?

Finally, the board is missing loads of components according the silk printing. One missing component is a small ceramic filter cap (SMD cap on the solder side) bypassing the two electrolytic capacitors above, before the choke.

Question #5: is there a bypass cap (SMD on the solder side) in the original HP power supply pack? Should I add one? Note: there is a ceramic SMD bypass cap between the pins of the departing cable.

Many thanks in advance to anybody who would have some answers.

Footnote: the zero volt output is connected to the earth pin of the IEC connector via the second thin PCB, and locky_z’s design isn’t having (or not so many) HF bypass caps either. Hence, any suggestion for improvements here? How ‘low-noise’ or ‘low-ripple’ has the PSU to be anyway?

I think I got myself the same SMPS (NETZTEIL FÜR HP 0957-2247 32V - 2500mA) and it works quite well "out of the box".
I had absolutely no problems with it and it is really just fine if you can live with its voltage and current limitations. I would not worry about tweaking anything in it as you are likely to do more harm than good. Why polish a turd?
Spend your money on DUTs